Reduction gearing



2 Sheets-Shen T. R O H.. S

REDUCTION GEARING Filed May 29, 1953.

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WITNESSES jana 3, L SHORT 1,893,042

REDUCTION GEARING Filed May 29, 1931 2 Sheets-Sheet 2 g) u 6% 53 Q *n F 1. l I --.l

INVENTOR ma SHORT.

ATTORN EY www' Patented `lan. 3, 1933 UNITED STATES waan Ina SHORT, .or EssINGroN, PENNSYLVANIA, AssIGNon To Wr-srINenoUsn nnncfrnrc a MANUFACTURING COMPANY, A CORPORATION or PENNSYLVANIA RnnUc'rioN cnam-NG Application filed May 29, 1931. Serial No. 540,897.

kMy invent-ion relates to reduction gearing and more particularly to that class Aoi gearvused, for example, to transmit power to a ship propeller from a steam turbine, operat- .ing at a relatively high speed, and it has for an object to provide 4an improved lubricating system for the gearing.

In the cla-ss of service referred to, large quant-ities of lubricant must be furnished to the bearings and to the yteeth vof the gears. The lubricant is `si-ipplied under pressure to the bearings and to a series of jets located adjacent the meshing teeth upon which a copious supply of lubricant is sprayed. The

r lubricant thrown oii by the gears, together with the drainage from the bearing, ordinarily drops to the bottom of the casing where a sump is formed. In many installations`v lubricant drainage from other apparatus, for example, the prime mover driving the gearing, is conveyed to the gear casingwhose sump functions as a general lubricant sump not only for the gear but other units associated with the gear A pumping means is provided to withdraw the lubricant from the sump and convey it under pressure to the working parts of the gearing; and, in some cases, as mentioned before, t-o the bearings of other units associated with the gearing. A large amount of work is expended in conveying this lubricant to the top of the gearing and it is an object of my invention to lessen this amount by reducing the head at whichfth'e pump must operate.

In practicing my invention, I provide a reservoir disposedy at an elevation higher than the sump, and adapted to catch a very1 substantial portion of the lubricant thrown off by the gears. I provide further means l0 for conveying to the reservoir lubricant drainage from the gear bearings. Only that portion of lubricant which escapes the reservoir finds its way to the sump, Where it is F transferred to the reservoir by a relatively smallv pumping means. The main pump gathers the lubricant Jfrom the higher level reservoir and conveys it under pressure to the working parts ot the gearing. It will be seen that the work expended in raising the lubricant is substantially reduced as the head at which the main pump must operate is reduced by the amount represented by difference in the oil level of the reservoir as compared to the sump.

It is, therefore, a prime object ofmy invention to provide this improved lubricant system by collecting a major portion of luprici-nt discharged by the gears at a high eve It is a. further object of my invention to accomplish this result without an objectional complicated structure but by one that will be simple to construct and which will be reliable in operation.

These and other objects are edecte'd by my invention, as will be apparent :trom the tollowing description and claims, taken in connection with the accompanying drawings forming a part of this application, in which:

Fig. 1 is a sectional view ot the gearing taken along the line I-I of Fig. 2;

Fig. 2 is a transverse sectional view of the gearing, with parts broken away for clearness; and,

Fig. 3 is a diagrammatic view showing piping connections when used with a prime mover.

Referring to Figs. 1 and 2, I show a reduction gear indicated generally by reference 10 comprising a casing 11 enclosing a gear 12 meshing with pinions 13, 13. The gear 12 has axially spaced toothed portions 15, meshing with the toothed portions 111 of the pinions 13. The gear 12 is carried by a driven shaft 16 journalled in bearings 17 and 18. Axial movement of the shaft is prevented by a thrust bearing 19. y The bearings 17 and 18 together with the thrust bearing 19 are supported by the casing 11.

The pinions 13, are journalled in bearings las divided walls 29 and 30 whichwith the bottom of the gear casing lll'and the U-shaped kwall 31 define a chamber 32.,

Reservoirs "33a are mounted in the casing 11 between the gear toothed portions 15 and the casing side wall 34 andy reservoirs 335 between said gear portion and side wall 35.

The reservoirs 33a and 335 have open upper portions 36 provided with baihes 37 `which are inclined toward the gear-,portions 15 and terminate adjacent thereto. Transverse ducts 38 and 39 (Fig. 1) form communication be- ,tween reservoirs 33a and 335 disposed on opposite sides of the casing 11 and conduits connect reservoirs 33a disposed side by side.

' Conduite 41 connect reservoirs 335 in a similar manner. Screens 42 are removably mounted in lateral guides 42a and are located between the open upper portions 36 and the openings 43 located adjacent the bottom of the reservoirs 33a and 335. Openings 425 providing access to the screens 42 and permitting their withdrawal from the guides 42a are located in side walls 34 and 35 in alignment with the guides 42a. The reservoir openings 43 provide communication between the reservoirs 33a and 335 and the chamber 32 which has an outlet 44 connected tothe main circulating ejector 45.

Lubricant for the meshing pinion and teeth gear and the pinion bearings 20, 21 and 22 is conveyed to passage 46 formed in each floating frame 23 by a conduit 47. Ports`48 connect the bearings 20, 21 and 22 with the passage 46 and the spraying jets 49 are supplied through the holes 50 in communication with the passage 46. Lubricant is discharged by the holes 50 to receptacles 51 formed in the Cil floating frames 23 and then flows from the receptacle by gravity through jets 49 to the vmeshing teeth of the gear 15. Lubricant is supplied to the thrust bearing 19 and journal bearing 18 by conduit 52 and to bearing 17 by conduit 53.

' Disposed beneath pinion bearings 20 and 22 are pans 54 and 55 into which drainage from the bearings 2O and 22 flows and it is then conveyed by openings or conduits 56 to the reservoirs 33a and 335, the discharge ends of theconduits 56 beingaligned with and above the open upper portions 36 of reservoirs 33a and 335. A substantial portion of the lubricant thrown olf by the gear when operating in counterclockwise direction, Fig. 1, is de- Leeaoia voirs 335 Vfunction to collect the lubricant thrown by the gear. l j

The lubricant discharge -frornthe thrust bearing 1 9 is conveyed by a conduit 57 the i end of which -is so ldisposed as -to .pour the contents in thereservoir 335 inthe-same manner as4 the conduits 56 associated with the L pans 54. j Y I f The lubricant draining 'fromth'e inner ends ot' journal bearings 17 and 18 drops to the sump=26 and fromtheouter .ends,theflow is to chambers 53 'formed in the casing 11 continuing to the sump 28 through openings 59 in casing end walls.

Transfer of lubricant, collected bythe sump, to the reservoirs is effected by auxiliary transfer ejectors 6() and 61 which have theirinlets connected tothe sump 28at 62 and 63, strainers 64y being interposed between the ejector inlets 62 and 63 and the sump 28.r The ejectors'60 and 61 discharge into the transverse reservoir connecting ducts 38v and 39 as shown at 62a and 630:.A Motivating fluid is conveyed to ejectors 60 and 61 and to the main circulating ejector 45 by means of conduit 65,) F f in Fig'3, the reduction gearing 10 is shown driven by a .steam turbine 66. The conduits 47, 52 and 53 are connected to a supply con-v duit 67 which conveys lubricant under'prest` sure from a pressure source, suchas an im'-Y peller type pump 66 mounted on the driving sha-lt 26. An orifice 69 is placed in conduit 67 for limiting the flow olubricant from the impeller so that the impeller discharge pressure may be used for governing pur'- poses, as is well known in the art. The turbine bearings 72 receive lubricant through branch conduits' 74 connected tothe supply conduit 67. The conduit jfor conveying motivatingv fluid to the ejectors 60, 61 and isconnected to the discharge side of the impeller 68. `Lubricant vdischarged by the tur# bine bearings 72 is drained through conduit 73 to the high level reservoirs 33a yand 335 The main ejector draws lubricant from the high level reservoirs 33a'and- 335 in the gear 'fi casing 11 and propels it through conduit 70 to the suction chamber 71 of the impeller 68. From the foregoing, it will be apparent that the purpose oi the present invention is to reduce the work of pumping'in a circulatory lubricating system. This is achieved by having the collection chambers of the system located at a relatively higher elevation than is customary, the elevated reservoirs 33a and V335 being locatedabove the sump. The

major .portion of the circulating lubricant goes directly to the elevated reservoirs, and theresidue of lubricant dripping from the gear, as well as drainage from the main bearings, going to the sump is pumped from i3" `the latter by the transfer ejectors 60 and 61 tothe elevated reservoirs. 1rWhile theiejector is shown as located below the gear cas ing, it will be apparent that' the elevated reservoirs and the U-shaped chamber 32 merely constiute means for providing a static head at. the inlet of the ejector so that the' effect is thesame as if the ejector Was connected directly to the elevated reservoirs 33a and 33e at a relatively higher level. Therefore,the present lubricating system talres care ofy all lubricating requirements and escaping or surplus lubricant is collectedand'supplied te the circulating pump in such a Way that thevvork ofthe latter is materially reduced; The transfer ejectors and 6l merely' func tien to drain lubricant-from the sump andl to supply it tothe elevated reservoirs,that is, to themain circulating system.

The U-sha-ped chamber 3.2, together with the elevated collection chambersor reservoirs 33a andi 335,*constitute a common storage spaceor'reservoir for supplyingl lubricant tothe inlet of the ejector 45. By having the chamber 32 U-shaped and suiiiciently narrovv, it maybe arranged in the space between adjacent-gear rims, as shownin Fig. l. Alsothe structure and arrangement of thel U- shaped chamber 32`and the elevated collec tion chambers orreservoirs 33a and' 33?) is such that the-levelof lubricant maybe main-- tained Without having the loWe-r sides of the gears-run in oil, the-gearing being adequately lubricated byapparatus associated With-the pinions, as already described. The common storagevspace is, therefore,- available for thecollection and maintenance of lubricant at; a relatively high level, and the gravity head. assistingthe ejector 45 is dependent upon'theelevat-ion'offthe liquid level above theV ej ectorl inlet. Therefore, any lubricant. added to the columnlabove'the ejector inlet has the advan tage `of being pumpedwvith' the assistance lof' gravity head. The ejector 45, of course, must elevate lubricant-from its'level to the level ofl the discharge point, and this pump-ing head Yis reduced to the extent ofthe assisting gravity head. The greater thel gravity head, the more the pumping capacity of the ejector 45, an'Y increase in gravity head being equivalent to a reduction in discharge head. The ejector l5'is'so designed and its supply of'motive: fluid is so controlled'that a normal elevated level of lubricant is maintained, and the apparatus tends to maintainan equilibrium. condition such that-'the level of lubricant is: substantially constant, fora lowering of level. reduces. the gravityhead and pumping capac-- ity and an increaseV in level has the contrary effect, With the result that, in normaloperation, the apparatus tends to maintain a sub-- stantially constant level.l The Work 'of pump-- ing lubricant is, therefore, reduced to the-V eXtent of"the assistance of gravity lhead of' lubricant added-to the'columnl above the-inlet;

side of the ejector 5l ln other Words, the present invention is a lubricating system wherein the Work of vpumping is reduced by taking' advantage of gravity, the present arrangement, due to static head provided, being equivalent to connecting the ejector 45 to the elevated reservoirs 33a and 33?) at the level thereof. Since a circulatory system is provided having elevated collection reser voirs, Which are advantageous to the extent of their elevation so far as pumping is concerned, it is necessary to elevate such lubricant as enters the sump 28 thereinto and the transfer ejectors G0 and 61 serve this purpose.

From the foregoing, it will be seen that the Work of circulating lubricant in my improvedsystem is reduced by having the reservoirs 33a and 33?) elevated with respect to the sump, that is, the suction load of the ejector i5 is reduced over an arrangement Where all the lubricant goes to the sump, to the extent of the quantity of oil caught or draining int-o the upper reservoirs; and, as the major portion of lubricant circulating in the system is caught in the elevated reservoirs 33a and 33?), 'the major portion of the lubricant is circu- .lated in the most efficient manner. The lubri- Icant which gravitates into the sump is raised 'to the level of the reservoirs 33a and 33?) by Ythe auxiliary or transfer' ejectors 60 and 6l.

.Hence, the principal advantage of my im- .'provement is the reduction in head for the main ej ectors l5 afforded by the elevated reservoirs 33a and 332).

lllhile l have shown my invention in but yone form, it will be obvious to those skilled Ain the art that it is not so limited, but is susceptible of various changes and modifications 'without departing from the spirit thereof, :and l desire, therefore, that only such limitak tions shall be placed thereupon as are im,- 'posed by the prior art or as are specifically set :forth in the appended claims.

What I claim is:

1. The combination with a pair of meshing ggears enclosed by a casing, of a lubricating :system for the gears including means for su'pplying lubricant to the gears, a sump arranged beloW the gears for collecting lubricant, circulating means for supplying lubricant to said supply means and including a :reservoir in said casing and adapted to catch .lubricant thrown olf by the gears, and means vfor conveying lubricant from the sump to the circulating means, said reservoir being :arranged above the sump inorder to reduce the Work of said circulating means in circulating lubricant.

2. The combination with a pair of meshing gears enclosed by a casing, of a lubricatiing system for said gears including means for supplying lubricant to the gears, a lubri- `cantsump arranged in said casing below the ggears, circulating' means for supplying lubricant to said supply means including a reserllO voirfineans for directing intosaid reservoir lubricant discharged by said gears, andpn'ieans for conveying lubricant from thefsump to the circulating means, saidvreservoir being arranged at a higher elevation than the sump in order'to reduce the work of said circulating means in circulating lubricant.

3. The combinationwitha pair of meshing gears enclosed by a casing, of a lubricating system for said gears including means for supplying lubricant to the gears, a sump for collecting lubricant disposed in said casing below the gears, circulating means for supplyinglubricant to said supply. means, including a reservoir adapted to catch lubricant thrown oh" by the gears and arranged between the sides of the gear-and the sides of casing, and means for conveying lubricant from the sump to the circulating means, said Vreservoir being arranged at a higher elevation than the sump in order to 'reduce the work of said circulatingmeans in circulating lubricant.

4. The combination with a pair of meshing gears enclosed by a casing, of a lubricating system for said gears includingl means for supplying lubricant to the gears,'a sump for collecting a portion of lubricant discharged by said gears and disposed below the same, circulating means for supplying lubricant yto said supply means including a reservoir between a side of one of the gears and a casing side wall, said reservoir having an opening and a deliector for directing into the opening ofthe reservoir a substantial porn tion oi'ilubricant thrown oii by the gears, and

means for conveying lubricant from said sump to said circulating means.

5. The coinbiii ation with a pair of meshing gears supported by bearings and a casing for enclosing thegearsvot a lubricating system including means for supplying lubricant to said gearsy and to the bearings, circulating nieans for supplying lubricant to said supply means and includinga reservoir disposed yin said casing and adapted to receive a substantial portion of .lubricant discharged by said gears and bearings, a sump formed iii the casing `below tliegears for receiving'the (remaining portion of lubricant discharged by the gearsand bearings., and means for con- Veying to said circulating means lubricant .collected in said sump, said reservoir being arranged at a higher elevation than the sump ,in order to reduce the work of the circulating means in circulating lubricant.

6. The combination with a pair oii meshing gears supported by bearings and a casing for enclosing said gears, of a lubricating system including means for supplying lubricant'to said gears and bearings, a lubricant sump formed in said casing at the bottom thereof, lcirculating means for supplying lubricant toysaid supply means vincluding a yreservoir disposed in the casing and adapted to receive a `portion of lubricant thrownv olii'V by said gears, ineans for conveying to said circulating means lubricant drainage from the bearings, and means for conveying lubricant in thesump to said circulating system, said reservoir being arranged at a higher elevation than the sump in order to reduce the work of the circulating means in circulating lubricant. i Y

7. The cov bination with a reduction gear including a pinion, adriving member for saidv pinion, bearings for supporting said driving member, a gearVV meshing with said pinion, a shaftfor said gear supported by bearings and a casing for enclosing said gears, of a lubricating system including means for supplying lubricant to said gears and bearings,v a suinp in said casing for collecting a portion of lubricant discharged by said gears and bearings, circulating means for supplying lubricant to saidsupply means including a reservoir disposed in the casing and adapted toreceive a substantial portion of the lubricant thrown ol:l by said gears, means for conveying to said reservoir lubricant drainage'from some of the'bearings, and means for conveying lubricant from said sump to said circulating means, said reservoir being arranged at a higher elevation than the ying belowy the gear, circulating means kfor supplying lubricant to said' supply means and including reservoirs, disposed in said casing at an elevation higher than said sump and having open upper portions provided with deectors inclined toward and terminatv ing adjacent to the teeth cfa gear and adapted to direct into said reservoirs a substantial portion of lubricant thrown oiiby saidgears, means for draining to said reservoirs lubricant discharged by some of the-bearings, and means for conveying lubricant from said sump to said reservoirs. Y

9. The combination with a pair of meshing gears including a driven gear enclosed by a casing,v of a lubricating system for the gears including means for supplying lubricant to said gears, a lubricant sump disposedA in the casing below the gears, circulating means for supplying lubricant to said supply means including reservoirs arranged in said casing on each side of said driven gear and between the toothed face of the gear andthe side walls of the casing, said reservoirs having open por-y 

